This invention relates to a laparoscopic cannula assembly or a trocar sleeve assembly. This invention also relates to a laparoscopic surgical technique involving such a cannula assembly.
Laparoscopy involves the piercing of a patient's abdominal wall and the insertion of a cannula through the perforation. Generally, the cannula is a trocar sleeve which surrounds a trocar during an abdomen piercing operation. Upon the formation of the abdominal perforation, the trocar is withdrawn while the sleeve remains traversing the abdominal wall. A laparoscopic instrument, such as a laparoscope or a forceps, is inserted through the cannula so that a distal end of the instrument projects into the abdominal cavity.
Generally, in a laparoscopic surgical procedure, three or four perforations are formed in the abdomen to enable deployment of a sufficient number of laparoscopic instruments to perform the particular surgery being undertaken. Each perforation is formed by a trocar which is surrounded by a sleeve, the sleeves or cannulas all remaining in the abdominal wall during the surgical procedure.
Prior to insertion of the first trocar and its sleeve, a hollow needle is inserted through the abdominal wall to enable pressurization of the abdominal cavity with carbon dioxide. This insufflation procedure distends the abdominal wall, thereby producing a safety space above the patient's abdominal organs.
Laparoscopic surgery provides several advantages over conventional incision-based surgery. The laparoscopic perforations, in being substantially smaller than the incisions made during conventional operations, are less traumatic to the patient and provide for an accelerated recovery and convalescence. Hospital stays are minimized. Concomitantly, laparoscopic surgery is less time consuming and less expensive than conventional surgery for correcting the same problems.
It frequently occurs during laparoscopic surgery that an additional instrument is temporarily required. Inserting this extra instrument involves either temporarily removing one of the other instruments or forming another perforation with a trocar.